Explore topic-wise InterviewSolutions in Current Affairs.

A small object is placed $50cm$ to the left of a thin convex lens of focal length $30cm$ . A convex spherical mirror of radius of curvature $100cm$ is placed to the right of the lens at a distance of $50cm$. The mirror is titled such that the axis of the mirror is at a angle $\theta ={30}^{\circ }$ to the axis of the lens, as shown in the figure.

If the origin of the coordinate system is taken to be at the centre of the lens, the coordinates $\left(incm\right)$ of the point $(x,y)$ at which the image is formed are

Two blocks, each having a mass $\text{M}$, rest on frictionless surfaces as shown in the figure. If the pulleys are light and frictionless, and $\text{M}$ on the incline is allowed to move down along the incline, then the tension in the string will be

Twelve wires, each having equal resistance r, are joined to form a cube as shown in figure (32-E20). Find the equivalent resistance between the diagonally opposite points a and f.

figure (32-E20).

A wheel starting from rest, rotates with $5{\text{rad/s}}^2$ angular acceleration along its axis. After $2\text{s}$ of motion, the magnitude of radial and tangential component of acceleration of the particle at a distance $2\text{cm}$ from the axis are ________ and ________ ${\text{cm s}}^{-2}$.

There is a small hole near the bottom of an open tank filled with a liquid. The speed of the water ejected does not depends on

The electric field associated with an $EM$ wave in vacuum is given by $E=40\cos (kz-6\times {10}^{8}t)\hat{i}$, where $E$, $z$ and $t$ are in $V/m$, meter and seconds respectively. The value of wave vector $k$ is

A narrow monochromatic beam of light of intensity $I$ is incident on a glass plate as shown in figure. Another identical glass plate is kept close to the first one and parallel to it. Each glass plate reflects $25\%$ of the light incident on it and transmits the remaining. The ratio of the minimum and the maximum intensities in the interference pattern formed by the two beams obtained after one reflection at each plate is $1:n$ . The value of $n$ will be

The time taken for a disc of radius R and rotating about its center with ${\omega }_0$ to stop when placed on the corner of a room such that the wall (coefficient of friction ${\mu }_1$) and the horizontal floor (coefficient of friction ${\mu }_2$ ) retard the disc, is

An object is cooled from ${75}^{\circ }\text{C}$ to ${65}^{\circ }\text{C}$ in $2$ min in a room at ${30}^{\circ }\text{C}$. The time taken to cool another identical object from ${55}^{\circ }\text{C}$ to ${45}^{\circ }\text{C}$ in the same room, in minutes is

Two stones are thrown up simultaneously from the edge of a cliff $240\text{m}$ high with initial speed $10\text{m/s}$ and $40\text{m/s}$ respectively. Which of the following graph best represents the time variation of relative position of the second stone with respect to the first? (Assume stones do not rebound after hitting the ground and neglect air resistance, take $g=10{\text{m/s}}^2$)

(The figures are schematic and not drawn to scale.)

A boat which has a speed of $5\text{m/s}$ in still water crosses the river of width $25\text{m}$ in 10 seconds. The boat is heading at an angle of $\alpha$ with downstream, where $\alpha$ is equal to

The spring balance A reads 2 kg with a block of mass m suspended from it. A balance B reads 5 kg when a beaker with liquid is put on the pan of the balance. The two balances are now so arranged that the hanging mass is inside the liquid in the beaker as shown in the figure, in this situation (given density of block > density of liquid)

A light ray travels from denser to rarer. Plot between $\delta$ (deviation) vs i (incidence angle) is shown in figure, then which is the correct relation between Y & X?

When a balloon rising vertically upwards at a velocity of 10 m per second is at a height of 45 m from the ground a parachutist bails out from the balloon after 3 second he opens the parachute and deaccelerates at a constant rate of 5 metre per second square then find

1. what is the height of the parachutist above the ground when he opens the parachute.

2. how far is he from the balloon at this instant.

3. with what velocity does he strike the ground.

4. what time does he take in striking the ground after his exit from the balloon.

(take g=10 metre per second square)

A point charge q is placed inside a conducting spherical shell of inner radius 2R and outer radius 3R at a distance of R from the centre of the shell. The electric potential at the centre of shell will be $\frac{1}{4\pi {ϵ}_0}$ times:

A transformer is used to light a $140\text{W}$, $40\text{V}$ lamp from $240\text{V}$ $AC$ mains. The current in mains cable is $0.7\text{A}$, find the efficiency of transformer.

A particular hydrogen like ion emits radiation of frequency $2.92\times {10}^{15}\text{Hz}$ when it makes transition from $n=3$ to $n=1$. The frequency (in $\text{Hz}$) of radiation emitted, in transition from $n=2$ to $n=1$, will be:

A point particle of mass m, moves along the uniformly rough track PQR as shown in the figure. The coefficient of friction, between the particle and the rough track equals $\mu$. The particle is released from rest, form the point P and it comes to rest a point R. The energies lost by the ball, over the parts PQ and QR of the track, are equal to each other, and no energy is lost when particle changes direction from PQ to QR. The values of the coefficient of friction $\mu$ and the distance x (= QR), are respectively close to

The number of photons per second on an average emitted by the source of monochromatic light of wavelength $600\text{nm},$ when it delivers the power of $3.3\times {10}^{–3}\text{watt}$ will be $(h=6.6\times {10}^{–34}\text{Js})$

A ring of mass M and radius R is rotating with angular speed $\omega$ about a fixed vertical axis passing through its centre O with two point masses each of mass $\frac{M}{8}$ at rest at O. These masses can move radially outwards along two massless rods fixed on the ring as shown int he figure. At some instant the angular speed of the system is \frac{3}{5}R from O. At this instant the distance of the other mass from O is:

Find the current in $6\Omega$ resistor in the circuit shown in the figure.

A parallel- plate capacitor of area A, plate separation d and capacitance C is filled with four dielectric materials having dielectric constant $k_1,k_2,k_3$ and $k_4$ as shown in the figure below. If a single dielectric material is to be used to have the same capacitance C in this capacitor, then its dielectric constant k is given by

1. 79.57

Out of the given state diagram of a Moore type sequence detector, which of it represents a ''110'' sequence detector?

Check the equation 1/2mvsquare=mgh is dimensionally correct or not

The magnitude of the resultant of two equal vectors is equal to the magnitude of either vector. What is the angle between the two vectors?